sr: fix coverity warning

[vpp.git] / src / vppinfra / clib.h

diff --git a/src/vppinfra/clib.h b/src/vppinfra/clib.h
index dac41ad..b3a2580 100644 (file)
--- a/src/vppinfra/clib.h
+++ b/src/vppinfra/clib.h
@@ -38,7 +38,15 @@
 #ifndef included_clib_h
 #define included_clib_h
 
+#include <stddef.h>
+
+#if __has_include(<vppinfra/config.h>)
 #include <vppinfra/config.h>
+#endif
+
+#ifdef  __x86_64__
+#include <x86intrin.h>
+#endif
 
 /* Standalone means to not assume we are running on a Unix box. */
 #if ! defined (CLIB_STANDALONE) && ! defined (CLIB_LINUX_KERNEL)
@@ -62,8 +70,8 @@
 #define ARRAY_LEN(x)   (sizeof (x)/sizeof (x[0]))
 
 #define _STRUCT_FIELD(t,f) (((t *) 0)->f)
-#define STRUCT_OFFSET_OF(t,f) ((uword) & _STRUCT_FIELD (t, f))
-#define STRUCT_BIT_OFFSET_OF(t,f) (BITS(u8) * (uword) & _STRUCT_FIELD (t, f))
+#define STRUCT_OFFSET_OF(t,f) offsetof(t, f)
+#define STRUCT_BIT_OFFSET_OF(t,f) (BITS(u8) * STRUCT_OFFSET_OF (t, f))
 #define STRUCT_SIZE_OF(t,f)   (sizeof (_STRUCT_FIELD (t, f)))
 #define STRUCT_BITS_OF(t,f)   (BITS (_STRUCT_FIELD (t, f)))
 #define STRUCT_ARRAY_LEN(t,f) ARRAY_LEN (_STRUCT_FIELD (t, f))
@@ -91,6 +99,16 @@
 #define __clib_weak __attribute__ ((weak))
 #define __clib_packed __attribute__ ((packed))
 #define __clib_constructor __attribute__ ((constructor))
+#define __clib_noinline __attribute__ ((noinline))
+#ifdef __clang__
+#define __clib_noclone
+#else
+#define __clib_noclone           __attribute__ ((noclone))
+#endif
+#define __clib_aligned(x) __attribute__ ((aligned(x)))
+#define __clib_section(s) __attribute__ ((section(s)))
+#define __clib_warn_unused_result __attribute__ ((warn_unused_result))
+#define __clib_export __attribute__ ((visibility("default")))
 
 #define never_inline __attribute__ ((__noinline__))
 
@@ -110,10 +128,18 @@
 /* Hints to compiler about hot/cold code. */
 #define PREDICT_FALSE(x) __builtin_expect((x),0)
 #define PREDICT_TRUE(x) __builtin_expect((x),1)
+#define COMPILE_TIME_CONST(x) __builtin_constant_p (x)
+#define CLIB_ASSUME(x)                                                        \
+  do                                                                          \
+    {                                                                         \
+      if (!(x))                                                               \
+       __builtin_unreachable ();                                             \
+    }                                                                         \
+  while (0)
 
 /*
  * Compiler barrier
- *   prevent compiler to reorder memory access accross this boundary
+ *   prevent compiler to reorder memory access across this boundary
  *   prevent compiler to cache values in register (force reload)
  * Not to be confused with CPU memory barrier below
  */
@@ -138,16 +164,8 @@
   decl __attribute ((destructor));             \
   decl
 
-/* Use __builtin_clz if available. */
-#if uword_bits == 64
-#define count_leading_zeros(x) __builtin_clzll (x)
-#define count_trailing_zeros(x) __builtin_ctzll (x)
-#else
-#define count_leading_zeros(x) __builtin_clzl (x)
-#define count_trailing_zeros(x) __builtin_ctzl (x)
-#endif
+#include <vppinfra/bitops.h>
 
-#if defined (count_leading_zeros)
 always_inline uword
 min_log2 (uword x)
 {
@@ -155,45 +173,6 @@ min_log2 (uword x)
   n = count_leading_zeros (x);
   return BITS (uword) - n - 1;
 }
-#else
-always_inline uword
-min_log2 (uword x)
-{
-  uword a = x, b = BITS (uword) / 2, c = 0, r = 0;
-
-  /* Reduce x to 4 bit result. */
-#define _                                      \
-{                                              \
-  c = a >> b;                                  \
-  if (c) a = c;                                        \
-  if (c) r += b;                               \
-  b /= 2;                                      \
-}
-
-  if (BITS (uword) > 32)
-    _;
-  _;
-  _;
-  _;
-#undef _
-
-  /* Do table lookup on 4 bit partial. */
-  if (BITS (uword) > 32)
-    {
-      const u64 table = 0x3333333322221104LL;
-      uword t = (table >> (4 * a)) & 0xf;
-      r = t < 4 ? r + t : ~0;
-    }
-  else
-    {
-      const u32 table = 0x22221104;
-      uword t = (a & 8) ? 3 : ((table >> (4 * a)) & 0xf);
-      r = t < 4 ? r + t : ~0;
-    }
-
-  return r;
-}
-#endif
 
 always_inline uword
 max_log2 (uword x)
@@ -227,6 +206,9 @@ min_log2_u64 (u64 x)
 always_inline uword
 pow2_mask (uword x)
 {
+#ifdef __BMI2__
+  return _bzhi_u64 (-1ULL, x);
+#endif
   return ((uword) 1 << x) - (uword) 1;
 }
 
@@ -245,6 +227,12 @@ is_pow2 (uword x)
   return 0 == (x & (x - 1));
 }
 
+always_inline uword
+round_down_pow2 (uword x, uword pow2)
+{
+  return (x) & ~(pow2 - 1);
+}
+
 always_inline uword
 round_pow2 (uword x, uword pow2)
 {
@@ -263,18 +251,6 @@ first_set (uword x)
   return x & -x;
 }
 
-always_inline uword
-log2_first_set (uword x)
-{
-  uword result;
-#ifdef count_trailing_zeros
-  result = count_trailing_zeros (x);
-#else
-  result = min_log2 (first_set (x));
-#endif
-  return result;
-}
-
 always_inline f64
 flt_round_down (f64 x)
 {
@@ -293,6 +269,15 @@ flt_round_to_multiple (f64 x, f64 f)
   return f * flt_round_nearest (x / f);
 }
 
+always_inline uword
+extract_bits (uword x, int start, int count)
+{
+#ifdef __BMI__
+  return _bextr_u64 (x, start, count);
+#endif
+  return (x >> start) & pow2_mask (count);
+}
+
 #define clib_max(x,y)                          \
 ({                                             \
   __typeof__ (x) _x = (x);                     \
@@ -307,6 +292,14 @@ flt_round_to_multiple (f64 x, f64 f)
   _x < _y ? _x : _y;                           \
 })
 
+#define clib_clamp(x,lo,hi)                    \
+({                                             \
+  __typeof__ (x) _x = (x);                     \
+  __typeof__ (lo) _lo = (lo);                  \
+  __typeof__ (hi) _hi = (hi);                  \
+  _x < _lo ? _lo : (_x > _hi ? _hi : _x);      \
+})
+
 #define clib_abs(x)                            \
 ({                                             \
   __typeof__ (x) _x = (x);                     \
@@ -325,6 +318,7 @@ void qsort (void *base, uword n, uword size,
 uword
 clib_backtrace (uword * callers, uword max_callers, uword n_frames_to_skip);
 
+#include <vppinfra/byte_order.h>
 #endif /* included_clib_h */
 
 /*